1. Field of the Invention
The present invention relates generally to acquisition of two-dimensional data from linear sensor arrays, and more particularly to high-speed acquisition of two-dimensional data from such arrays.
2. Description of the Prior Art
The desirability of determining two-dimensional data, i.e., the size and/or profile of objects or particles in two dimensions, utilizing a linear sensor array and sampling the condition of the array periodically has, in the broad sense, been recognized and used effectively for some time. For example, the RETICON image sensors use linear arrays which are periodically sampled. In general, the sampling of the array is done on a sensor by sensor basis, and a bit from each sensor across the array is stored consecutively in a single shift register. U.S. Pat. No. 3,692,980 describes, in conjunction with other not necessarily germane sampling equipment, the use of a photocell array wherein the data is loaded into a single shift register. This approach is entirely satisfactory for the purpose for which it is intended, but is inadequate for high-speed events wherein relatively small objects or particles move rapidly across the sensor array. The sampling frequency is limited by the rates at which the sensors can be individually sampled in a single sweep. In some instances, the object being measured may move appreciably during the sampling from one end to the other end of the sensor array.
A number of other means for counting and sizing particles exist. U.S. Pat. No. 2,958,464 discloses one approach to this end, but utilizes a two-dimensional array of sensors.
Also, it is not an uncommon requirement to sample random events which provide data at an extremely high rate during the event, but since the events are not constant, do not, on an average, provide data at an overall high rate. None of the above approaches provide a means for receiving and storing data at a high instantaneous rate while providing for a more convention data output rate for supplying data to conventional systems.